Cardinals To Promote Brycen Mautz For Debut
Cardinals left-hander Brycen Mautz will be called up for his MLB debut on Sunday, relays Derrick Goold of the St. Louis Post-Dispatch. He’ll slide into the rotation with St. Louis coming off a doubleheader on Saturday. The team has yet to announce the move.
It’ll be the second straight day with a big-league debut for the Cardinals, who promoted infielder/outfielder Bryan Torres on Friday. The longtime minor leaguer didn’t get into the first game against the Reds, but started both matchups of Saturday’s twin bill. Torres recorded three hits across the two games.
Mautz has delivered a sub-3.00 ERA across nine starts at Triple-A this season. He’s striking out more than a batter per inning, but his 13.5% walk rate is a career-worst mark. The 24-year-old is not among the upper tier of prospects in the St. Louis system, but he’s generally among the top 20 in the organization. FanGraphs‘ James Fegan ranked Mautz at No. 17 heading into the season, while MLB Pipeline had him at 20th.
The Cardinals selected Mautz in the second round of the 2022 draft out of the University of San Diego. The lefty posted decent results in his first pro season, recording a sub-4.00 ERA at Single-A. He took a step back in High-A the following year, with a 5.18 ERA to go with a 4.86 FIP. Mautz came through with a breakout season in 2025. He cruised to a 2.98 ERA with a career-best 28.6% strikeout rate in 25 starts at Double-A. Mautz was named the organization’s minor league pitcher of the year last season.
This could be a brief stint for Mautz, as the Cardinals don’t have a clear hole in the rotation. The group has remained healthy and generally provided decent results. Veterans Dustin May, Matthew Liberatore, and Andre Pallante haven’t excelled on a per-inning basis, but they’re offering length each time they take the ball. Michael McGreevy is off to a strong start. Kyle Leahy‘s transition to the rotation has gone reasonably well.
Photo courtesy of Jim Rassol, Imagn Images
Cardinals Select Four Players
The Cardinals added four prospects to their 40-man roster on Rule 5 protection day: Outfielder Joshua Baez, catcher Leonardo Bernal, and left-handers Cooper Hjerpe and Brycen Mautz. They needed to open one spot, so they designated reliever Jorge Alcala for assignment.
St. Louis signed Bernal as an international free agent in 2021. MLB.com ranks him 4th among the organization’s prospects. Bernal hit .270 with 10 home runs over 96 games at High-A in 2024, earning a bump to Double-A. He scuffled to a 64 wRC+ in a brief sample with Springfield. Bernal was back with the Double-A squad this past season. He put together a league-average performance in terms of wRC+, while chipping in 13 home runs and 13 steals. The 21-year-old has shown decent base-stealing prowess for a catcher, swiping 20 bags over the past two years.
The Cardinals selected Baez in the second round of the 2021 draft. He’s the team’s 11th-ranked prospect on MLB.com. A bloated strikeout rate held Baez back in his first few professional seasons, but he got the contact in check this past season. After three straight years with a strikeout rate above 34%, Baez trimmed it to 20.6% across two levels in 2025. He also showed a new level of power, reaching 20 home runs between High-A and Double-A. Baez had totaled 24 home runs in his previous four professional seasons. He also racked up 54 stolen bases this past year.
Hjerpe is one of the team’s top arms in the minors, but he’s currently on the shelf after undergoing Tommy John surgery back in April. The lefty sits at 13th on MLB.com’s prospect list. Hjerpe was a first-rounder back in 2022. He posted a solid 3.27 ERA between High-A and Double-A in 2024. Hjerpe had a strikeout rate above 35% at both stops.
Mautz was taken in the second round back in 2022. He’s immediately jumped into a workhorse role as a professional, making at least 23 starts in all three of his seasons. Mautz struggled to a 5.18 ERA at High-A in 2024, but bounced back with his best season yet this past year. The lefty posted a 2.98 ERA with a career-best 28.6% strikeout rate across 114 2/3 innings at Double-A in 2025. The 24-year-old is a candidate to make starts at the big-league level at some point next season.
Alcala was claimed off waivers from the Red Sox back in August. He was knocked around in 15 appearances with the Cardinals, recording a 5.02 ERA. The 30-year-old had spent his entire MLB career with the Twins heading into 2025. He was dealt to Boston in June and made 19 appearances for the team before being designated for assignment and landing in St. Louis.